Film advance mechanism for combination visual and sound apparatus

ABSTRACT

A driving mechanism is operatively connected to a sprocket wheel for rotating the wheel and advancing the frames of a film. An adjusting knob is further provided, which enables manual rotation of the sprocket for fine adjustment of the frame location.

United States Patent Youngblood [151 3,662,936 1 May 16,1972

[54] FILM ADVANCE MECHANISM FOR COMBINATION VISUAL AND SOUND APPARATUS [58] Field olSearch ..226/49, 51, 76, 127, 152, 174; 352/163, 164, I69, l87

[56] References Cited [72] Inventor: Donald A. Youngblood, Chalfont, Pa.

UNITED STATES PATENTS [73 1 Ass'gnee' 2 Cmpmtbn 2,037,454 4/1936 Boecking ..352/I63 2,299,973 10/ l 942 Getten ..226/ 76 [22] Filed: Apr. 6, 1970 21 Appl.N0.: 31,012

Related us. Application Data [60] Division of Ser. No. 739,909, June 14, I968, abandoned, which is a continuation of Ser. No. 535,149, Mar. 17, 1966, abandoned.

[52] US. Cl ..226/5l, 226/76, 226/l52,

Primary Examiner-Richard A. Schacher Att0rney-D. R. Pressman [57] ABSTRACT film. An adjusting knob is further provided, which enables manual rotation of the sprocket for fine adjustment of the frame location. 226/174, 352/169 [5 l] Int. Cl. ..G03b l/24 I 6 Claims, 12 Drawing Figures Patented May 16, 1972 8 Sheets-Sheet i.

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FILM ADVANCE MECHANISM FOR COMBINATION VISUAL AND SOUND APPARATUS This is a division of parent application Ser. No. 739,909, filed 6-14-68 (now abandoned), which parent application in turn is a continuation of grandparent application Ser. No. 535,149, filed 3-17-66 (now abandoned). Three other divisional applications of said parent application (Ser. Nos. 25,707; 25,805, and 31,071 and .filed the same date hereof) describe inventions closely related to the present application.

This invention relates to an entertainment and/or educational device and more particular to a now continuous film advance mechanism for a combination visual and sound apparatus.

Combination audio and visual devices are known to be an important tool of education as well as sales. That is, where untrained teachers or salesmen are used, a device which combines a visual production with an audio background enables the untrained to present to a potential client or student a complete and well prepared program. I

These combination visual and sound devices, however, have been inadequate because they are either inflexible or too difficult to operate for an untrained worker. At present, those which are easy to operate are so because they do not allow flexibility of programming. The device must be prepared in advance in the factory for presentation of a sound and film program and thus is able to show only a single presentation. In order to show an additional oralternate audio-visual presentation, it is necessary that the apparatus be transmitted to the factory which produced the apparatus originally and be returned with a difierent program. Or the user must have a plurality of such devices, one for each program.

Those devices which are flexible enough to present various programs are difficult to operate. The operator of such a device must be given an intensive orientation as to the capabilities of the machine and must be capable of trouble shooting if any disorder results. These devices normally require threading of the film through the various guide and sprocket wheels in the device. If it is necessary to use a different sound track with the pre-threaded film, the operator is required to manually synchronize the audio with the visual presentation.

Therefore there has been a recognized need for a combination visual and sound presentation device which is flexible enough so that various programs may be shown in the device, yet is so uncomplicated to use that a relatively unskilled person may operate the device. For example where the device is to be used in various countries, the sound track should be easily interchangeable so that a plurality of sound tracks may be used with a single film. However, the device must be easy to operate.

It is, therefore, an object of this invention to provide a new and improved combination visual and sound apparatus.

Another object of the invention is to provide a new and improved visual and sound apparatus which is both portable and easy to operate.

Another object of the invention is to provide a combination visual and sound apparatus which readily handles a plurality of programs and which is adapted to easily interchange the audio and visual contents of a program.

Another object of the invention is to provide a new and improved film advance mechanism for a visual and sound apparatus.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein only those drawings necessary to explain the invention of the present divisional application have been retained.

FIG. 1 is a front view of the inside according to the invention.

FIG. 2 is a rear view of the inside components of said device.

FIG. 3 is an sectional view taken along the line 3-3 in FIG.

components of a device FIG. 4 is a sectional view taken along the line 4-4 of FIG.

FIG. 5 is an enlarged fragmentary sectional view taken along the line 5-5 in FIG. I;

FIG. 6 is an enlarged sectional view taken along the line 6- 6 in FIG. 2;

FIG. 7 is an enlarged sectional view taken along the line 7- 7 in FIG. 6;

FIG. 8 is an enlarged sectional view taken 8 in FIG. 7;

FIG. 9 is an enlarged sectional view taken along the line 9- 9 in FIG. 2;

FIG. 10 is an enlarged sectional view taken along the line 10-10 in FIG. 9;

FIG. 11 is an enlarged sectional view taken along the line 11-11 in FIG.10;

FIG. 12 is an enlarged sectional view similar to FIG. 4 with the cartridge receptacle in an open position;

The present audio visual device comprises a sound projector which can display the frames of a cartridge-mounted endless filmstrip in noncontinuous sequence in response to control signals from the second track of an endless audio tape, which is mounted in a subcartridge within the cartridge. After the cartridge is inserted into a receptacle in the projector, the receptacle is pivoted into the projector, whereupon a sprocket wheel in the projector engages the filmstrip.

The sprocket wheel 78 is best seen in FIGS. 6 and,7 and is comprised of a pair of circular discs 416 which are vertically disposed and have sprocket teeth 418 equally spaced about the periphery thereof. Discs 416 are separated by an integral cylindrical body portion 420 having an axially extending cylindrical bore. Sprocket wheel 78 is telescoped over shaft 422 so that the shaft extends through the bore in body portion 420. Sprocket wheel 78 is secured to the shaft by a threaded fastener 423 which is threadedly secured in body portion 420 and bears against the outer surface of shaft 422.

As best seen in FIG. 5, shaft 422 extends through openings in the side walls 425 of base 390 and extends to a film advancing assembly 424 (FIG. 10). Shaft 422 is rotatably mounted within base 390. The shaft is restrained against longitudinal movement by means of a collar 426 which is tightened about the end of the shaft 422 by means of a threaded fastener. A similar collar 428 is mountedabout shaft 422 adjacent the opposite side wall 425 of base 390 and is tightened about the shaft by a threaded fastener. As best seen in FIG. 12, the sprocket wheel is located adjacent a rectangular opening 431 in main supporting plate 326. A portion of each of circular discs 416 extend through opening 431 to the opposite side of the supporting plate 326. Thus, as cartridge receptacle 40 is moved into the apparatus, cartridge 42 is engaged by the circular discs 416 of sprocket wheel 78. The sprocket wheel extends into cartridge 42 in slots provided therefor which are adjacent to the film. Thus, the rotation of shaft 422 results in the advancement of the film in cartridge 42. Opening 431 also provides a window for the image to be projected through to lens 202.

As best seen in FIGS. 1, 9, 10, and 1 I, the film advancing assembly 424 comprises in addition to solenoid 76, a drive wheel 430, a cam disc 432, a single frame advance disc 434, a drive cone 436, and an adjusting knob 438. The film advancing assembly 424 is supported by a mounting bracket 440 which includes an L-shaped base portion 442. L-shaped base portion 442 comprises a rectangular planar portion 444 which is along the line 8- disposed horizontally and is secured to the inner lower wall central portion 450 which is integral with the vertical 256 (see FIG. 4) by suitable fasteners 445 and a vertically extending rectangular planar leg 446 which is integral with portion 444 and is disposed vertically. The solenoid 76 is secured to the mounting bracket 440 at leg 446 by fasteners 448.

The mounting bracket 440 further includes an L-shaped leg 446 of the base portion 442. Portion 450 is comprised of a planar rectangular horizontally disposed leg 452 and a rectangular vertically disposed planar leg 454. The vertical leg 454 includes an opening through which shaft 422 extends and is supported thereby. As best seen in FIG. 10, shaft 422 has a washer 456 which is telescoped thereover. Washer 456 includes a cylindrical portion 457 which also extends through the opening in leg 454 of the bracket. The washer 456 is precluded against longitudinal movement within the opening in leg 454 and along shaft 422 by a collar 458 which is similar to collars 426 and 428 and which is maintained tightly about shaft 422 by a threaded fastener 460. Washer 456 provides a low friction surface between shaft 422 and leg 454 so that shaft 422 may rotate easily therein.

Mounting bracket 440 further includes an L-shaped top portion 462 which includes a horizontally disposed planar rectangular leg 464 and a rectangular planar vertically disposed leg 466. A planar tab 468 which is rectangularly shaped is upstruck from horizontal leg 464 and is disposed vertically. Vertical leg 466 is bifurcated by virtue of a slot 470 which extends to the end 472 of the leg 466. Leg 454 of central portion 450 of the mounting bracket 440 includes an outstruck tab 474 which is rectangular, planar and vertically disposed. A finger 476 is pivotably connected to tab 474 by a fastener 478. The function of finger 476 will be seen hereinafter.

As previously mentioned, shaft 422 is connected to film advancing assembly 424. Drive wheel 430 is loosely mounted about shaft 422 so that it rotates easily with respect to the shaft. It is restrained against longitudinally movement with respect to shaft 422 by a split spring collar 480 which is secured to the shaft within an annular groove 482 which is provided on the outer surface of shaft 422.

Drive wheel 430 is generally cylindrical and includes an annular groove 484 which extends about the periphery thereof. Groove 484 is flared towards the outer surface at 486 thereby providing an enlarged opening to the groove. The drive wheel 430 further includes an integral portion 488 which is smaller in diameter than the major portion of the wheel and which is also cylindrical. The remaining portion of drive wheel 430 is a substantially cylindrical portion 490 which is integral with and adjacent portion 488 which includes a flat edge 492 by virtue of a chordally shaped portion having been removed.

Cam 432 is best seen in FIG. 11 and has an opening similar to the outer periphery of portion 490 of the drive wheel 430 and is secured thereon by press fitting portion 490 in said opening. Cam disc 432 is mounted about drive wheel 430 so that it rotates eccentrically with respect to shaft 422. That is, cam surface 494 of disc 432 varies along its periphery in distance from the center of shaft 422.

A pawl 496 is connected to the cam disc 432 adjacent the ortion 498 of disc 432 which is the portion of the disc with the greatest diameter. Pawl 496 is pivotably mounted to disc 432 about fastener 500which is preferably a rivet. Pawl 496 has a finger 502 the purpose of which will appear hereinafter. The single frame advance disc 434 is pivotably mounted about shaft 422 adjacent the disc 432 of pawl 496. Pawl 496 is connected to the cam disc 432 by a spring 501. Cam disc 432 includes an opening 503 adjacent its outer surface which is adapted to receive and engage a first end of spring 501. Pawl 496 includes an opening 505 in which the opposite end of spring 501 is engaged. The normal tendency of spring 501 is to draw pawl 496 towards shaft 422. That is pawl 496 is urged against the outer surface of a portion of single frame advance disc 434, as will be seen hereinafter.

As best seen in FIG. 10, single frame advance disc 434 comprises a first portion 504 which is substantially cylindrical, a central portion 506 which is somewhat wafer-shaped and includes four flat surfaces 508 (FIG. 9) which are each equally spaced from each other and lie in a separate quadrant of the central portion 506. Flat portions 508 are separated by arcuate surfaces 510. Between each flat surface 508 and arcuate surface 510 is a detent or notch 512 which is somewhat larger than the thickness of finger 476. Each of the detents 512 is connected to an arcuate surface 510 via a flat radially extending shoulder 513. The shoulders 513 act to limit the rotation of the single frame advance disc 434 by abutting finger 476 after the disc has been rotated to advance the film. Finger 476, after it stops disc 434 by abutting shoulder 513, is urged into detent 512 by a U-shaped spring 514 which is connected between finger 476 and tab 468.

The remaining portion 515 of single frame advance disc 434 is best seen in FIG. 9. Portion 515 is generally cylindrical and includes four ratchet teeth 517 which are equally spaced about the periphery of portion 515. Teeth 517 have radially extending shoulders 519 which each face in the same direction about shaft 422. Pawl 496 is urged against the periphery of portion 515. The remaining surfaces of teeth 517 provide a gradual increase in the diameter of the portion 515 so that pawl 496 may be gradually urged away from the shaft 422 if the pawl is moved in a first direction. However, if moved in the opposite direction, finger 502 of pawl 496 engages the shoulder 519 of the teeth and draws the single frame advance disc 434 with drive wheel 430.

Spring 514 is generally U-shaped and includes an L-shaped end 516 which extends through an opening which is provided in tab 468. The L-shaped end 516 maintains the spring 514 in the opening in tab 468. Spring 514 also includes an L-shaped end 518 which extends through an opening provided in finger 476. The shape of end 518 maintains spring 514 in the opening in finger 476.

Finger 476 is located within slot 470 so that it may pivot vertically about the horizontal axis through fastener 500. The normal tendency of spring 514 is to have its legs diverge. Thus, finger 476 is urged away from tab 468 against the outer periphery of the central portion 506 of single frame advance disc 434. When finger 476 is engaged in any of the notches 512, the single frame advance disc 434 is restrained against any rotation. As will be seen hereinafter, finger 476 enables the single frame advance disc 434 to be rotated a discrete amount each time it is moved. That is, finger 476 engages the next notch 512 after each rotation of the disc for advancement of the film. Engagement of finger 476 into the next notch thereby enables the single frame advance disc to be rotated only a quarter revolution each time it is used to advance the frame of the film in cartridge 42. The finger 476 also prevents rotation of single frame advance disc 434 when a framing adjustment is made and the film is moved less than a complete frame length. Thus finger 476 may be used as a releasable locking means for the single frame advance disc 434.

As best seen in FIG. 9, cam surface 494 of cam disc 432 is adapted to lift finger 476 vertically as drive wheel 430 is rotated. As previously mentioned, the cam disc 432 is fixedly mounted to drive wheel 430 and therefore rotates therewith. In this manner, rotation of the drive wheel frees finger 476 from notch 512, thus enabling the single frame advance disc 434 to move with respect to finger 476.

The single frame advancedisc 434 is separated from drive wheel 430 by a shim 520 to prevent friction between cam disc 432 and drive wheel 430. The shim 520 is substantially cylindrical and is mounted about shaft 422 within a cylindrical recess in the disc 434. The shim is thicker than the depth of the recess so that the parts are separated.

The separation of drive wheel 430 from single frame advance disc 434 is further enhanced by shaft 422 which includes a portion 521 of smaller diameter which extends to adjusting knob 438. A shoulder 523 is formed at the interface between portion 521 of shaft 422 and the main portion thereof. The shoulder 523, as well as a lateral face of drive wheel 430, abut shim 520 which thereby maintains a space between the drive wheel and single frame advance disc 434. The drive cone 436 is secured to the single frame advance disc 434 by fasteners 522 which extend through disc 434 and are threadedly engaged in cone 436. Thus drive cone 436 is secured to disc 434 for rotation about the axis of shaft 422. The drive cone 436 has a frusto-conical mating portion 524 which is tapered at its end. The mating portion 524 of the drive cone 436 is preferably comprised of an elastomeric material such as rubber and is adapted to engage the adjusting knob 438.

Adjusting knob 438 is generally cylindrical and includes a female frusto-conically shaped mating section 526 which presents a flared opening to receive the mating section 524 of the drive cone 436. As the mating section of the drive cone and adjusting knob 438 make contact, they are frictionally engaged to prevent relative rotation between the two.

Adjusting knob 438 is mounted on shaft 422 so that it is longitudinally slidable with respect thereto. Adjusting knob 438 has an enlarged cylindrical end member 528 which has a knurled outer surface 530 which adapts the adjusting knob 438 to be rotated manually. The adjusting knob 438 also includes a cylindrical bore 532 which extends through the enlarged member 528 and in which an end button 534 is secured to the end of shaft 422.

The button 534 also includes a cylindrical bore which is substantially similar in diameter to shaft 422 and in which shaft 422 is secured by a pin 536. Pin 536 extends through a transverse opening in shaft 422 and radially extending openings in button 534. Button 534 is movable within bore 532 of adjusting knob 438. That is, the adjusting knob 438 may be moved longitudinally with respect to shaft 422. Button 534 is fixedly secured to shaft 422. Thus, as adjusting knob 438 is moved with respect to the shaft 422, button 534 is moved within bore 532. However, adjusting knob 438 is secured rotationally to shaft 422 by a keying pin 538 which is mounted in a longitudinally extending notch in shaft 422 and a similar complementary longitudinally extending notch in the adjusting knob 438. The'adjusting knob 438 is urged against the drive cone 436 by a spring 540 which is axially mounted about shaft 422 within bore 532 of the adjusting knob. Thus, the normal tendency of the spring 540 is to urge button 534 out of bore 532. To disengage the adjusting knob 438 from drive cone 436 it is therefore necessary to draw the adjusting knob towards button 534. The button 534 is then inserted deeper in bore 532.

By gripping the adjusting knob 438 at the shoulders 542 and sliding the adjusting knob in the direction of arrow 544, adjusting knob 438 is disengaged from the drive cone 436 and the single frame advance assembly. The rotation of the adjusting knob while it' is manually urged away from drive cone 436 enables shaft 422 to rotate without drive wheel 430, cam 432, single frame advance disc 434 or drive cone 436 being rotated. That is, when adjusting knob 438 is slid in the direction of arrow 544, mating section 524 of drive cone 436 is drawn out of mating section 526 of adjusting knob 438. The adjusting knob 438, though disengaged from drive cone 436, is still keyed to shaft 422 by keying pin 538. Thus, rotation of the adjusting knob 438 rotates shaft 422. The drive cone 436 is stationarily maintained against rotation in that it is secured to single frame advance disc 434 which is fixed against rotation by the engagement of finger 476 in a notch 512. Drive cone 430 and cam disc 432 are also not moved for reasons which will hereinafter appear. Thus the adjusting knob 438 enables rotation of the shaft and subsequent rotation of the sprocket wheel 78 for adjustment of the film for framing puroses.

p Referring now to FIG. 1, it can be seen that a cylindrical shaft 546 of solenoid 76 is connected to drive wheel 430 via a wire 548. As best seen in FIGS. 9 and 10, wire 548 is wrapped as a coil in groove 484 of the drive wheel 430. It is secured against sliding in groove 484 by a fastener 550 which extends axially through a portion of drive wheel 430 and into groove 484 to secure the inner loops of the coil in the groove. The first end of wire 548 is terminated in a loop 552 which is secured to shaft 546 by a suitable fastener 554. As best seen in FIG. 1, the end of shaft 546 is bifurcated by virtue of a slot 556. The loop 552 is secured to the shaft 546 within slot 556 by fastener 554 which extends through the loop and openings provided therefor in the walls of the shaft.

The other end of wire 548 is terminated in a loop 558. Wire 548 is connected by loop 558 to a spring 560 which is best seen in FIGS. 2 and 9. The end of spring 560 extends through loop 558 to secure the spring to the loop. Spring 560 is connected at its other end to a fastener 562 which is connected to a bracket 564. Bracket 564 is connected to the inner lower wall 256 of the apparatus 30 by a fastener 565.

As best seen in FIG. 1, an L-shaped bracket 566 is connected to the mounting bracket 440 by a fastener 567. The top leg 568 of bracket 566 which is best seen in FIG. 10, is planar, horizontally disposed and is also bifurcated at its end by virtue of a slot 570. Slot 570 provides a guide for the wire 548 to prevent transverse movement thereof. As best seen in FIG. 9, a pad 571 is provided between the top leg 568 of bracket 566 and the end of shaft 546. Pad 571 acts as a cushion between the top leg 568 and shaft 546 to lessen the impact and noise when shaft 546 is released from solenoid 76. The top leg 568 of the bracket acts as a stop to prevent the shaft from being completely disengaged from the body of the solenoid 76.

In operation, each time solenoid 76 is energized shaft 546 is pulled down in the direction of arrow 572. As shaft 546 is so pulled, wire 548 rotates the drive wheel 430 in the direction of arrow 574 in FIG. 27. The cam disc 432 is likewise drawn in the direction of arrow 574. The shaft 422 is not rotated as a result of finger 476 being engaged in one of the notches 512. Thus disc 434 cannot rotate. Disc 434 is fixedly secured to drive cone 436 which is therefore also prevented against rotation. Since drive cone 436 is frictionally engaged with adjusting knob 438, adjusting knob 438 does not rotate. Therefore, shaft 422 cannot rotate because it is not rotatably slidable within the adjusting knob 438 as a result of keying pin 538. Thus, only drive wheel 430, cam disc 432 and pawl 496 are rotated as the wire 548 is drawn by shaft 546. Therefore shaft 422 is not rotated when the shaft 546 is drawn downwardly by solenoid 76.

As drive wheel 430 and cam disc 432 rotate in the direction of arrow 574, cam surface 494 of disc 432 urges the finger 476 upwardly in the direction of arrow 576. When the shaft is completely drawn into the body of solenoid 76, a portion of surface 494 has lifted finger 476 sufficiently so that is is drawn above arcuate surface 510 of the periphery of the central portion 506 of single frame advance disc 434. Concurrently, as drive wheel 430 and cam 432 are drawn down by wire 548, pawl 496 is drawn over the next tooth 517 of the single frame advance disc 434 and finger 502 thereof engages the tooth. After the energization of solenoid 76 is terminated, the tension applied to wire 548 of spring 560 overcomes the pull exerted by shaft 546 and thereby draws the drive wheel 430 in the direction of arrow 578 in FIG. 9. As drive wheel 430 is drawn in the direction of arrow 578, finger 502 of pawl 496 which is engaged with the next tooth 517 of the single frame advance disc 434 also draws disc 434 in the direction of arrow 578. The rotation of disc 434 causes the drive cone 436 and adjusting knob 438 to rotate.

Thus shaft 422, being keyed to adjusting knob 438, is rotated and the film in the cartridge is advanced. As disc 434 rotates in the direction of arrow 578, the finger 476 is urged downwardly by spring 514. The finger 476 is thus lowered since cam disc 432 also rotates in the direction of arrow 578, thereby reducing the diameter of the portion of cam surface 494 adjacent finger 476. The finger is thus moved lower than the arcuate surface 510 of the next quadrant of portion 506 of the single frame advance disc 434. Thus when the radially extending shoulder 513 of the next quadrant of the disc 434 reaches finger 476, it is stopped as the lateral surface of finger 476 abuts the shoulder. The finger 476 drops into notch 512 adjacent the abutting shoulder 513 and the single frame advance disc 434 is locked against further movement. In this manner, the single frame advance disc is moved only a discrete angular distance each time. That is, it rotates each time the advance solenoid 76 is energized. It can therefore be seen that the shaft 422 may be rotated and the film moved thereby in either of the following ways:

1. When adjusting knob 438 is pulled outwardly in the direction of arrow 544 and the knob rotated, shaft 422 is rotated for film adjustment or framing purposes; or

2. When solenoid 76 is energized, shaft 422 is rotated for advancing the film one frame. It should be noted that the 90 rotation of the single frame advance disc, in the direction of arrow 578, results in the movement of the film a single frame. Thus framing is maintained throughout by means of the single frame advance disc. Where adjustment is required, it is necessary only to disengage the adjusting knob 438 from drive cone 436 and rotate shaft 422 until the proper framing adjustment is made.

As best seen in FIG. 10, adjusting knob 438 is supported by a frusto-conically shaped mounting bracket 580 which is preferably secured to wall 80 of the apparatus 30 by welding. Wall 80 includes a circular opening 582 which communicates with the inner contents of the mounting bracket 580. The mounting bracket 580 includes a circular opening 584 in the circular planar wall 586 thereof. A nylon circular disc 587 is mounted within opening 584 by means of integral perpendicularly extending pegs 588 each of which include a hook type head that grasps wall 586 at the periphery of opening 584. The nylon disc 587 includes a circular opening at its center through which adjusting knob 438 extends. A smooth surface is provided by the nylon disc at its opening for rotation of adjusting knob 438 within bracket 580.

It can be seen that enlarged portion 530 of adjusting knob 438 is disposed substantially in the plane of wall 80 of the projector and is therefore easily accessible for manual adjustment.

Each time advance solenoid 76 is energized in response to a signal on the control track of the audio tape, shaft 546 is drawn downwardly and thereby draws wire 548 in the same direction. The drive wheel 430 (FIG. 10) is rotated in the direction of arrow 574 shown in FIG. 9. The cam surface 494 of cam disc 432 urges finger 476 in the direction of arrow 576 as the disc is rotated in the direction of arrow 574 with drive wheel 430. Simultaneously, pawl 496 is drawn over the next tooth 517 of single frame advance disc 434 and engages the tooth at shoulder 519.

When the signal terminates, the circuit through winding 1068 of solenoid 76 is broken. The shaft 546 is thus no longer drawn towards the solenoid. The pull of spring 560 is then the greater force drawing wire 548 and the spring thereby causes wire 548 to draw drive wheel 430 in the direction of arrow 578. As drive wheel 430 so rotates, the single frame advance disc 434 is drawn by pawl 496 in a similar direction. The drive cone 436, which is connected to the single frame advance disc 434, also rotates with the disc. Adjusting knob 438 is firmly engaged to the drive cone 436 and also rotates. The shaft 422 is keyed to adjusting knob 438 by keying pin 538 so that shaft 422 also rotates in the direction of arrow 578.

Shaft 422 is connected to sprocket wheel 78 which is engaged with film strip 728 (FIG. 12) through slots 714 and thereby advances the film a single frame as a result of the rotation of shaft 422.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their legal equivalents, the invention may be practiced otherwise than as specifically described.

What is claimed as the invention is:

1. In combination with a system for displaying individually a plurality of frames of a movable strip of film, a frame advancing assembly, said assembly including a sprocket wheel adapted to engage said film for movement thereof, said sprocket wheel secured to an axially extending rotatable shaft which is adapted to rotate said sprocket wheel, a drive wheel rotatably mounted about said shaft, an advance disc having a plurality of teeth which are equally spaced about its periphery and which is rotatably mounted about said shaft adjacent said drive wheel, a solenoid having a selectively movable member which is connected to said drive wheel for rotation of said drive wheel in a first direction, a spring connected to said drive wheel for rotation thereof in a second direction, a drive cone secured to said advance disc and adapted to rotate about said shaft with said disc, an adjusting knob mounted on said shaft adjacent said drive cone, said knob being secured to said shaft for rotational movement with said shaft, said knob being axially slidable along said shaft to selectively engage said drive cone to prevent relative rotation therebetween, said drive wheel adapted to rotate said disc when said wheel is rotated in said second direction, whereby said sprocket wheel is rotated to advance the frame of said film, said sprocket wheel also being rotated by rotation of said knob when said knob is disengaged from said drive cone.

2. Theinvention of claim 1 wherein said shaft further includes an enlarged member secured at an end thereof adjacent said adjusting knob, a spring axially mounted about said shaft, said spring mounted between said enlarged member and said adjusting knob, said spring adapted to urge said adjusting knob away from said enlarged member, and against said drive cone for frictional engagement therewith.

3. The invention of claim 2 wherein said advance, disc further includes an enlarged portion having a notched outer periphery, said notches each including a radially extending shoulder and a chordally extending surface, said shoulder and said surface separated by a radially extending detent, a pivotably mounted locking finger, said locking finger adapted to engage said advance disc in said detent, a cam disc secured to said drive cone for rotation therewith, said cam disc adapted to disengage said finger from said detent when said drive cone is rotated in said first direction, said finger adapted to limit the movement of said advance disc in said second direction by abutment of the axially extending shoulder of the next notch of said advance disc.

4. The invention of claim 3 wherein said finger prevents rotation of said disc in either direction when engaged in said detent whereby said adjusting knob may be manually urged towards said enlarged member so that it is disengaged from said drive cone, said adjusting knob thereby enabling rotation of said sprocket wheel for fine adjustment of the location of said frames of said film.

5. The invention of claim 4 wherein said drive wheel is secured to said spring and said movable member of said solenoid by an elongated wire, said wire having a first end connected to said spring and a second end connected to said member, a central portion of said wire being wrapped about said drive wheel so that when said solenoid is energized, said member pulls said second end of said wire which urges said drive wheel in said first direction and when said solenoid is deenergized, said spring pulls said first end of said wire for rotation of said drive wheel in said second direction.

6. The invention of claim 5 wherein said cam disc includes a pivotable pawl and rotation of said drive wheel and said cam disc in said first direction enables said pawl to engage the next tooth on the periphery of said advance disc so that movement of said drive wheel in said second direction draws and said advance disc, said drive cone and said adjusting knob in said second direction with said drive wheel so that said shaft rotates said sprocket wheel which in turn advances the frame of said film.

i l l i 

1. In combination with a system for displaying individually a plurality of frames of a movable strip of film, a frame advancing assembly, said assembly including a sprocket wheel adapted to engage said film for movement thereof, said sprocket wheel secured to an axially extending rotatable shaft which is adapted to rotate said sprocket wheel, a drive wheel rotatably mounted about said shaft, an advance disc having a plurality of teeth which are equally spaced about its periphery and which is rotatably mounted about said shaft adjacent said drive wheel, a solenoid having a selectively movable member which is connected to said drive wheel for rotation of said drive wheel in a first direction, a spring connected to said drive wheel for rotation thereof in a second direction, a drive cone secured to said advance disc and adapted to rotate about said shaft with said disc, an adjusting knob mounted on said shaft adjacent said drive cone, said knob being secured to said shaft for rotational movement with said shaft, said knob being axially slidable along said shaft to selectively engage said drive cone to prevent relative rotation therebetween, said drive wheel adapted to rotate said disc when said wheel is rotated in said second direction, whereby said sprocket wheel is rotated to advance the frame of said film, said sprocket wheel also being rotated by rotation of said knob when said knob is disengaged from said drive cone.
 2. The invention of claim 1 wherein said shaft further includes an enlarged member secured at an end thereof adjacent said adjusting knob, a spring axially mounted about said shaft, said spring mounted between said enlarged member and said adjusting knob, said spring adapted to urge said adjusting knob away from said enlarged member, and against said drive cone for frictional engagement therewith.
 3. The invention of claim 2 wherein said advance disc further includes an enlarged portion having a notched outer periphery, said notches each including a radially extending shoulder and a chordally extending surface, said shoulder and said surface separated by a radially extending detent, a pivotably mounted locking finger, said locking finger adapted to engage said advance disc in said detent, a cam disc secured to said drive cone for rotation therewith, said cam disc adapted to disengage said finger from said detent when said drive cone is rotated in said first direction, said finger adapted to limit the movement of said advance disc in said second direction by abutment of the axially extending shoulder of the next notch oF said advance disc.
 4. The invention of claim 3 wherein said finger prevents rotation of said disc in either direction when engaged in said detent whereby said adjusting knob may be manually urged towards said enlarged member so that it is disengaged from said drive cone, said adjusting knob thereby enabling rotation of said sprocket wheel for fine adjustment of the location of said frames of said film.
 5. The invention of claim 4 wherein said drive wheel is secured to said spring and said movable member of said solenoid by an elongated wire, said wire having a first end connected to said spring and a second end connected to said member, a central portion of said wire being wrapped about said drive wheel so that when said solenoid is energized, said member pulls said second end of said wire which urges said drive wheel in said first direction and when said solenoid is de-energized, said spring pulls said first end of said wire for rotation of said drive wheel in said second direction.
 6. The invention of claim 5 wherein said cam disc includes a pivotable pawl and rotation of said drive wheel and said cam disc in said first direction enables said pawl to engage the next tooth on the periphery of said advance disc so that movement of said drive wheel in said second direction draws and said advance disc, said drive cone and said adjusting knob in said second direction with said drive wheel so that said shaft rotates said sprocket wheel which in turn advances the frame of said film. 